A fanlisting is a list of fans, nothing more and nothing less. It costs nothing but a moment of your time to join, and if you have a website you can add a button to show your support. If you're not quite sure what this is all about, feel free to read more about it here. Otherwise, if you're a fan, join the fanlisting!
(PS: if you came here from TFL, this is not the site index! You can find that over here.)